Ice maker



Sept. 13, 1955 H. c. sHAGALoFF ICE MAKER '7 Sheets-Sheet l Filed Dec. lO, 1952 BY WQ@ ATTORNEY Sept. 13, 1955 H. c. sHAGALol-F 2,717,498

ICE MAKER Filed Dec. l0, 1952 7 Sheets-Sheet 2 I N V E N TOR. #95W y 6.' 'wafu of;

/TTORNEY Sept. 13, 1955 H. c. SHAGALOFF 2,717,498

ICE MAKER I Filed Deo. l0, 1952 7 Sheets-Sheet 3 TTORNEY Sept. 13, 1955 Hc. SHAGALOFF ICE MAKER 7 Sheets-Sheet 4 Filed Dec. l0, 1952 TTORNEY Sept. 13, 1955 H. c. SHAGALOFF ICE MAKER 7 sheets-sheet 5 Filed Dec. lO, 1952 INI/ENTOR. kwr'swazaf /ITTORNEY Sept. 13, 1955 H. c. sHAGALoFF lICE MAKER 7 Sheets-Sheet 6 Filed De'c. l0, 1952 INI/ENTOR.

d TTOR NE Y Sept- 13, 1955 H. c. SHAGALOFF 2,717,498

ICE MAKER Filed Dec. lO, 1952 '7 Sheets-Sheet '7 BY W@ TTORNEY United States Patent O ICE MAKER Harry C. Shagaloff, Evansville, Ind., assignor to Servei, Inc., New York, N. Y., a corporation of Delaware Application December 10, 1952, Serial No. 325,097

38 Claims. (Cl. 62-6) This invention relates to automatic making, harvesting, drying, and storing of ice pieces, generally called ice cubes.

This invention relates particularly to an ice maker like that disclosed and claimed in the copending patent application of Sven W. E. Andersson, Serial No. 205,519, filed January 1l, 1951.

Briefly, the above copending Andersson application discloses an ice maker wherein an ice mold is divided into ice forming compartments, each having a generally arcuate contour so that pieces of ice may be readily turned or swept from the mold by relative turning movement between the mold and the ice pieces. The ice removing 4action is automatic, as is the lling of the mold, freezing,

and loosening of the ice pieces. The ice pieces are detained for thorough drying before discharge to storage. The automatic operation is stopped short of discharge of ice to storage, and remains suspended during the time that a desired quantity of ice pieces is held in storage. in the specific structure disclosed in the above Andersson application, power for operating the ice release and the control mechanisms is provided by a hydraulic motor which also measures and delivers a quantity of water to the ice mold for freezing. The disclosure of the above copending Andersson application may be considered a part of this instant application and may be referred to for a detailed description of parts thereof that are common to the two patent applications.

This invention relates also to an automatic ice maker like that disclosed and claimed in a second copending patent application of Sven W.' E. Andersson, Serial No. 325,145, tiled December l0, 1952. Briefly, in this second copending Andersson application, there is disclosed an automatic ice maker wherein the ice ejector mechanism is driven by an electric motor. As described in this second Andersson application, the electric motor is geared down and is of a type that stalls while energized when the ejector mechanism contacts the ice frozen solidly in the mold, without burning out or otherwise damaging the motor. After the ice has been thawed free of the mold, as by electric heating elements, the electric motor resumes the turning movement of the ejector mechanism which sweeps the ice pieces from the mold, bringing them to rest upon the top of the ejector mechanism whereupon the motor and ejector mechanism are automatically stopped, pending the freezing of the next batch of ice in the mold. The disclosure of this second Andersson application may also be considered a part of this instant application and reference may be made thereto for a detailed description of the electric motor and related parts.

When water is being frozen into ice cubes in a conventional ice tray in a conventional refrigerator, it makes little difference which cube freezes first, which freezes last, or at what temperature the evaporator or cooling element operates so long as it is below 32 F. In the case of an automatic ice maker, the ice release cycle must not be instigated until all of the cubes are frozen. This presents "ice a problem for location of the temperature sensing element and the choice of temperature for instigating an ice release.

For example, if the ice tray is metal and the thermostat bulb that instigates an ice release is in Contact with the metal, the release temperature must be low, say 0 F., when the room temperature is normal or low, since the ice tray may be that cold before all of the cubes are frozen. This is due to the thermal insulating effect of the first ice to freeze. At the same time, to avoid freez ing temperatures in the food compartment of the refrigerator, it may not be desirable to permit the evaporator to go as low as 0 F. Then, in a high temperature room the refrigerating machine may not be able to produce a temperature as low as 0 F. so that all ice cubes may be completely frozen but a release cycle could not be instigated. Also, the necessity of establishing low evaporator temperatures in order to start an ice release cycle, may result in a long delay between the time the cubes are fully frozen and a release is started, thereby reducing the quantity of ice which can be automatically supplied in a given length of time. Thus, a wide variety of compensating devices are required which would be impractical t0 design, manufacture and keep in adjustment. Therefore, a design is required which permits the instigation of an ice release cycle at a relatively high temperature, say 25 F. while making sure that all the cubes are frozen under all operating conditions.

In accordance with this invention, the rear end of the ice mold is made of plastic or other heat insulating material and a copper slug, imbedded in the plastic, houses the thermostat bulb. The plastic closure member, which contacts the water in the rear compartment of the mold, causes the rear ice cube to be the last to freeze, and the copper slug keeps the thermostat bulb close to the temperature of the unfrozen water in the rear compartment of the mold. Thus, when this last cube freezes, the thermostat bulb temperature drops and a release cycle is instigated. With this arrangement, a thermostat set at 20 F.25 F. will result in fully frozen cubes through a wide range of room temperatures for both compression and absorption type refrigerating machines with different styles of evaporators. Also, the ice maker may be installed in a modern household refrigerator having a plurality of compartments that are maintained at different temperatures, some above and some below freezing, without interfering with the normal operation of such refrigerator.

Furthermore, an automatic ice maker, particularly where such ice maker is adapted to be used with a household refrigerator as in this case, requires the use of a foolproof thermostat for instigating ice release and mold filling cycles. Failure of the thermostat may cause water to ow continuously or at inopportune time to the ice mold. Sub-atmospheric charged bellow systems have been tried but abondoned because of their operating characteristics not permitting accurate temperature setting without altitude compensation.

In accordance with this invention, there is provided a diaphragm system wherein the ice mold thermostat operates above atmosphere pressure and instigates an ice release cycle on falling pressure, while at the same time, if the pressure falls below normal, instigation of a subsequent release cycle is prevented. The thermostat must be automatically reset before an ice release cycle can be completed. Thus, if the thermostat loses its charge or is otherwise inoperative, the ice maker stops in a position with the water valve closed to the ice mold.

Also, incorporated in this invention is a novel structure for supplying a measured quantity of water to the ice mold. The specific structure for supplying a measured quantity of water to the ice mold is the invention of Clyde E. Ploeger and is disclosed 'and claimed in his copending patent application Serial No. 325,085, led December l0, 1952. This structure, as will be described in detail hereinafter, eliminates the need for pressure seals or packing onrmoving'partsyit eliminatesthe lneed for accurately machined-*surfaces; it eliminates-thehazard of leaks developing after long service; it operates on low water pressure, will vwithstand high water pressures, and -may` be located in any position either above or below the -ice mold; it provides a'closed system that is sanitary and free from difiiculty occasioned by precipitates or foreign matter in the water. Briefly, this structure includes a metal measuringchamber generally'in theform of a hollow hemisphere having-a peripheral iiange around 'the open end thereof and rclosed by a circular cover plate thatis attached'to vtheange by screws. A' exible `rubberdiaphragmis attached at `its periphery between the cover and theflangeof the hemisphereeand is capable of conforming to-'the Shape ofthe hemisphere, in an extended position. Anopening is provided inthe bottomI center of the hemisphere yand* a lrod having ahead on one end thereof in contact with; the under surface ofthe diaphragm passes through th'e'iopening. A spring -encircles the rod and is compressed when the diaphragm is extended. A suitable water 4connection having an inlet vand an voutlet valve therein' is connected tothe center portion of the cover plate. With the inlet valve open, water flows into the measuring chamber extending the diaphragm which pushes the rod downward, thereby filling the chamber with a measured Aquantity of water'and compressing the spring. Then, at the proper time, the inlet valve is closed and the outlet valve opened whereby the spring expands forcing the rod and the diaphragmupward, discharges the water through the outlet valve and a connecting conduit into the ice mold.

Also, in accordance with this Vinvention,'once an ice ejectingcycle is started bythe complete freezing of the water yin the lice mold and consequent energizing of the ejector-motor, the ejector motortakes over'and', through la pluralityof cams mounted on-the motor shaft, `controls the heating of the mold, the ejecting of the ice, the resetting vof the mold thermostat, Vthe deenergization and energization ofthe compressor motor, the opening and closing of lthe water valves for filling the mold with a measured Iquantity of water, the stopping vof'the ice makerwhen lthe storage receptacle is-iilled and/ or'if the mold thermostat loses its charge orvbecomes otherwise inoperative, and thevdeenergization of -the ejector'motor at the' completion of the ejecting cycle, all by a simple compact and -`foolproof mechanism and without any complicated lswitches, compensators or'the' like. Amanually operated switch is provided for discontinuing the operation of the "ice makerwhile continuing operation of therefrigerator compressor at will. A switch operated by the refrigerator -door is provided for stoppingthe ice maker and energizing 1a lightfin the refrigerator when the door is open, and for vstarting the ice maker and deenergizing the interior light -when the door is closed.v

The invention, together with its objects and advantages,

'is set forth in more technical detail in the following deyrefrigerator in section;

Fig. 4 is a vertical section on line 4-4 of Fig. 3` looking in the direction of the arrows;

Fig. 5 is a vertical section on line 5 5 of Fig. 3 with parts broken away and looking in the direction of the arrows;

Fig. 6 Vis a rear elevation of the ice mold with parts in section and other parts broken away;

Fig. '7 is a' transverse vertical section through the ice mold and showing the ice resting on the ejector for drying;

Fig. 8 is a horizontal section through the rear portion of the ice mold;

Fig. 9 is a vertical section through the rear portion of the ice mold;

Fig. 10 is a front elevation of the ice maker showing parts of the refrigerator in section;

Fig. 11 is a rear elevation-of the ice maker showing parts of the water measuring device in section;

Fig. 12 is a detail vertical section of a part of the water conduits;

Fig. 13 is a rearelevation similar to Fig.- 11- and show ing the water valves in section; and

Fig. 14 is a perspective of a household refrigerator incorporating the ice maker.

General description Referring to Figs. 1 and 2, L1 and L2 are the two sides of a 1.15 .volt A. C. supply circuit. is a double ,pole double throw manually operated switch, shown in the on position to operate the ice maker. In the offv position the lower blade 20a ,of switch 20-will be .at terminal 21, which is dead, andthe upperblade 20h will be at terminal 22, which keeps the .compressor motor 24 running under control of a thermostat 25 in .the refrigerator. Thus, in the off lposition of switch 2t), all circuits to .the ice maker are broken, but the refrigerator continues to operate under the influence of the thermostat 25. Normally, current isfed to -the'ice maker .from L1 through switch blade 2Gb, connector 20d, switch blade 20a and through the terminal 23 of switch 20. If the stop switch 26 is open, indicating that the storage receptacle 27 is full of ice cubes, the ice maker stands idle. If the stop switch is closed, as shown inFig. l, nothinghappens until the mold thermostat 28 snaps the -switch 29 to the terminal 30 indicating .that the water in the ice mold 32 has been completely frozen into ice.

Adouble pole double throw pushbutton switch operated automatically by therefrigerator door-is indicated generally by numeral 34 and is shown in the closed door position. In theA open door position, Vtheujgsper blade 34a of switch 34 snaps from-terminal 35 to terminalft, .which is. dead, and thelower blade 34b snaps to terminal y37, toenergize a light 33 within the refrigerator. rlhus, the ice maker cannot run while the yrefrigerator door is open. With the refrigerator door closed, the interiorlight 38 is deenergized and the ejector motor .4@ and the mold heater 41 maybe energized. The high temperature limit switch 42 shownaheadof-the mold heateris a thermostatic device the IuQld 32 andcause the energized. ejectorrnotor 40 .inthermal contact with the mold which .opens Athe heater .cir-cuit at about and opens only in the event that .the mold heater is energized too long due to something having .gone wrong with thecontrols.

rIhe starting position `of the. ejector shaft is the position ithas when water is beingfrozen in the mold and the'previous batch of ice cubes is resting on the-ej ctor blades44, as shown .in Fig. 7. Whenthe wateris completely frozen Vtoicein the mold, the mold thermostat v28 lsnaps theswitch29 to terminal-30 (Fig. l) energizing the ejector -motor 4.tand the moldheaterl. vThus the ejector motor begins toy rotate, and ataboutthe 45 point .of rotation the:outlet valvc53, Awhich stands .open during the freezing cycle, is closed. AWhen the ejector mctor has .rotatedtthe shaft 43 and attached blades 44 about 63 the water inlet valve is opened by the earn/$5.1 and water begins to ow from the source of supply into the measuring vessel S4. Rotation of the ejector shaft continues until at about the blades 44 Contact the sciiti ice to stall. The mold heater 41 (300 watts) continues toA heat and mold, and the reset heater 5t) (l0 watts) continues to heat the mold thermostat bulb 28a so as to reset the switch 29 to the position shown in Fig. 1. When the ice is thawed loose in the mold by the heater 41, rotation of the ejector motor continues whether or not the mold thermostat 2S has reset. That is, current ows through terminal 30 if the mold thermostat has not reset and through terminals i7 and 31 if it has. The Water inlet valve 52 closes at about the 225 point of rotation of the ejector motor.

When the ejector blades 44 reach the 270 rotation point, a cam 56 on the ejector shaft 43 quickly raises the stop switch 26 to the broken line position, Fig. 4, breaking the ejector motor circuit at that point. If the mold thermostat 23 has reset this does not stop the ejector motor since it is getting current through terminal 31 from terminal 47 of the microswitch 46 (Fig. l). But if the mold thermostat has not reset, opening of the stop switch 26 stops the operation since the ejector motor has been getting current from terminal 3() of the mold thermostat Z8. The reset heater 59 remains energized, trying to reset the mold thermostat, and if it is successful rotation of the ejector continues; but if it is not successful it indicates that the mold thermostat has lost is charge, cannot be reset, and the 4system dies permanently, with the ejector motor and mold heater deenergized, the compressor motor deenergized, the water valve to the ice mold closed and the thermostat reset heater energized. In this way a diaphragm system may be used in the mold thermostat which operates above atmospheric pressure and instigates an ice ejecting cycle on falling pressure, while at the same time, if the pressure falls below normal, a subsequent ejecting cycle is prevented from being started. That is, if the mold thermostat 28 loses its charge, an ice release cycle will be instigated regardless of whether or not the water in the mold is completely frozen; but the ejector motor will rotate only to the 270 point whereupon the stop switch 26 is opened, the ejector motor deenergized and no more water is supplied to the mold until the defective thermostat has been replaced.

Going back to where the stop switch 26 opened, the ejector blades are at 270, but the mold thermostat 28 is reset. Rotation continues since the ejector motor is getting current through terminal 31 from terminal 47 of the micro switch 46 (Fig. l). At about 300 of rotation the stop .switch 26 drops free of its cam 56 and its circuit is either made or not, depending on how much ice is in the storage receptacle 27. The water outlet valve 53 is opened by the cam 5b at the 315 point of rotation, permitting the measured charge of water to be forced from the measuring vessel if-i to the mold. Having made sure that the ejector motor itl is getting current from terminals 47 and 31, so at 360 of rotation the microswitch 46 snaps away rom terminal 47 to terminal 43, deenergizing the ejector motor, the mold heater and the reset heater and bringing the ejector blades back to the starting point with the batch of ice resting thereupon to be dried during the next freezing cycle, with the compressor motor 24 energized, all as shown in Fig. 1. The water outlet valve remains open during the freezing cycle and is closed at the point of rotation of the ejector motor on the next release cycle.

Ice mold Referring now to Figs. 3 to 9, inclusive, the ice mold 32 comprises an aluminum die casting divided into a plurality of ice forming compartments 6l) by transverse partitions 6l. The ice forming compartments are generally semi-circular in transverse section, and the partitions are tapered horizontally from the right to the left side thereof as viewed in Fig. 8. The partitions have substantially no taper in the vertical direction. The partitions are each provided with an upstanding projection 62 on the right side and with a weir or notch 63 in the left side thereof. The outer surface of each of the weirs is of the same general curvature as the inner surface of the ice mold compartments, and the inner surface of the weirs is substantially vertical. The mold is provided with an upstandingedge 64 along the left side thereof, and the end walls 65 and 66 slant outward from right to left as viewed from the front in Fig. 3. The mold heater 41 is in the form of a hairpin coil and is located in slots 67 in the bottom of the mold at each side thereof. The mold rests on a refrigerated shelf 68 that is cooled by a refrigerating coil 69 also is in the form of a hairpin. As shown, the refrigerating coil is formed out of round on one side for good thermal contact with the undersurface of the refrigerated shelf and for downward ow of refrigerant from the inlet to the outlet end of such coil, The refrigerating coil is connected to a suitable refrigerating machine, not shown. As shown, the mold is provided with a plurality of bosses 70 projecting from the bottom thereof which pass through openings in the refrigerated shelf, and which clamp the mold to the shelf and the shelf to the refrigerating coil by means of a clamp 71, held in place by a plurality of screws 72 threaded into the bosses 70, A mounting plate 73 made of thermal insulating material is attached to the front end of the mold by a plurality of screws 74.

The rear ice forming compartment of the mold is closed by a combined closure member and mounting plate 66 that is formed of plastic or other thermal and electrical insulating material. A copper heat transfer plug 75 is imbedded in the plastic closure member 66, with the front surface thereof in contact with water in the rear compartment of the mold. The plastic closure member and the copper plug each have an opening or well extending transversely therethrough (Fig. 8) to receive the bulb or temperature sensing element 28a of the mold thermostat 28, which bulb is placed in good thermal contact with the copper insert. A compartment 76 (Figs. 8 and 9) is provided in the rear of the plastic closure member 66 and has located therein the thermostat reset heater Si), which also is in thermal contact with the copper insert. The compartment 76 is closed by an insulating plate 77 that is held in position by a plurality of screws 7S threaded into the rear of the ice mold casting, which screws hold the plastic closure member in place on the rear of the mold to close the rear ice forming compartment. A sealing gasket 79 is located between the rear of the ice mold casting and the front of the plastic closure member. The high temperature switch 42 for the mold heating element 41 is clamped in thermal contact with one side of the mold casting. The plastic closure member 66 is provided with a boss 80 (Fig. 9) having a downwardly and inwardly inclined opening therethrough for the reception of a water tube 81, and as shown in Figs. 4 and 5, the closure member is provided with an abutment 82 for locating the water tube. The bottom portion of the inclined opening is provided with a capillary V-notch 83 (Fig. 5) for conveying drip Water from the end of the water tube to the rear compartment of the ice mold. A rubber grommet 84 closes the transverse opening in plastic closure member 66.

The water freezes in the mold substantially in the manner shown in Fig. 2. That is, as the freezing progresses, cubes 1, 2, 3 4, 5 and 6 will freeze more or less uniformly with a small quantity of unfrozen Water in the upper center portion of each of the cubes, because heat is being absorbed by conduction through the metal bottom and both adjoining metal partitions of the mold, and by convections through the air above the mold. But cube No. 7 progresses in the manner shown with a slightly larger quantity of unfrozen water near the copper insert, because here heat is being conducted primarily through the bottom and only one metal partition of the mold and through the air above the mold; the end wall 66 being made of plastic which is a poor heat conductor. This forces cube No. 7 to be the last to freeze. When the rst six cubes are fully frozen, No. 7 Will have proceeded a little further than shown in 'Fig 2, but there will still be some unfrozen water near the inner face of the copper insert 75, thereby keeping the copper insert and the thermostat bulb 28a in the neighborhood of 32 F. The refrigerated shelf 68, however, may be much colder. Also, the ambient temperature around the outside of the plastic closure member 66 may be very low, say 0 F., since the whole ice mold assembly is in the freezing compartment of the refrigerator, but the high heat conductivity of the copper insert makes the temperature of the sensing .bulb 28a follow the temperature of the unfrozen water in the rear compartment of the mold because the bulb is insulated from the refrigerated shelf and from the low ambient byV the plastic closure member. Thus, 'the last water of the last cube to freeze must have been frozen before the thermostat bulb 28a can reach 25 F. This permits 25 F. to be a safe temperature for instigating a release cycle under all conditions of operation while making sure that all of the cubes are completely frozen. It has been found that when using a 300 watt heater to effect loosening of the cubes from the mold the insulating effect of the plastic closure member may preventthe thermostat bulb 28a from resetting by the'time the cubes are loosened. Therefore, some heat is supplied directly to the copper insert 66 and from there to the thermostat bulb during a release cycle by thethermostat reset heater 50. The reset heater may be replaced by a heat exchange member of high heat conductivity placed'betweenthe mold heater 41 and the thermostat bulb 28a.

E jector mechanism The ejector mechanism (Fig. 3) includesthe shaft 43 mounted for clockwise rotation at its `front end in the front mounting plate 73 and at its rear end'in the 4closure member 66. The shaft has a flat portion`85 on'the upper part thereof (Figs. 4 and 5 ),'and-is provided with a plurality of ejector blades 44, one for each ice mold compartment, at one side of the shaft. As shown in Figs. 4 and 5, the ejector shaft is mounted-off center lrelative to the longitudinal axis ofthe mold and the blades 44 are at an angle to the flat portion -85 of the shaft. The electric motor 40 (Fig.` 3), for driving the ejector shaft 43, is mounted by a pair of bracketsA 89-on amounting plate 90 on the rear wall 91 `of the refrigerator,v and is connected to the rear of the ejector shaft by a universal coupling 92. This electric'motor is geared down from 3400 R. P. M. to approximately-211.?. Mand'iscf a type motor that stalls while energized when Vthe-ejector blades initially contact the ice frozen'solid in the mold. An electric motor of this type is illustrated and described in the above copending patent application of VSven 'W. E. Andersson, Serial No. 325,145, filed December 10,` 1952. The connecting member 92 is provided with a notched universal coupling-93 at each end thereof to receive the end of the motor shaft at one end and ofthe-ejector shaft at'the other end. The middle portion -95 of Athe connector member is made of a phenolic cloth laminate or other suitable thermal and electrical insulatingl material. A-spool 96 made of suitable thermal insulating material encircles the connecting member and forms a guide therefor and a protecting shield for the insulation located between the rear wall members of the refrigerator.

Stop switch The stop switch 26 (Figs. 31 and 4) comprises a' channel member .100 that is generally AL-shaped in plan Yand is connected by a pivot pin 101 tothe upper right side of the rear closure member 66. An insulating spacer 102 is provided on the pivot pin between the rear of the closure member and the rear inner portion of the channel member. A vane 103 made of a thermal and -electrical insulating material is ,attached to the longitudinal portion 104 of the channel member and projects downwardly therefrom. The channel member lis provided with a rearwardly extending arm y105 (Fig. 9) thatV isfadapted to be contactedby the cam member :56.imounted upon a reduced `portion of the ejector shaft 43 and held in position thereon by a cotter key 106. The cam 56 is so shaped that upon rotation of the ejector shaft the cam contacts the rearwardly extending arm of the channel member and gradually raises the channel member to a substantially horizontal position as shown in broken lines in Fig. 4. Then the cam leaves the arm and permits the channel member to fall by gravity to its normal position shown in full lines. A mercury switch 107 is mounted on the transverse portion 108 of the channel member by an adjustable bracket 109 ina manner that when the channel member is in the full drawn position shown in Figs. 4 and l0 the circuit through the mercury switch 107 is closed, whereas when the channel member is in the broken line position of Fig. 4 the circuit is open.

Mold Jllz'ng device Referring to Figs. lland 13, the structure for filling the ice mold 32 with a measured quantity of water includes the measuring vessel 5ft-connected to a suitable supply of water by a conduit 110 having the inlet valve 52 therein; The valve 52 has an inlet connection 1,11 leading from the source of the supply and an outlet connection '112 including a conduit 113 leading to the measuring vessel 54. The conduit 113 has a T-connection and a conduit 114 leading to the outlet valve 53, which outlet valve has'an inlet connection 115 leading thereto and an outlet connection having a conduit 116 leading therefrom to the icevrnold 32. The measuring vessel 54 (Fig. l1) is attached to the mounting plate 90 and is vformed of an aluminum casting having an upper portion 117 of generally hemispherical shape with an outwardly projecting flange 118 at the upper end thereof and a lower portion 119 of cylindrical shape having a sleeve or guide member 120 projecting upwardly from the lower portion thereof into the bottom ofthe hemispherical portion. A cover plate 121 made of copper or other suitable material is attached to the open end of the measuring chamber by aplurality of set screws 122, several of which screws hold the measuring vessel on the mounting plate 90. A flexible rubber diaphragm 123 is fitted within the hemispherical portion of the measuring vessel and is secured therein by a peripheral flange portion 124 located between the flange'118 of the measuring Vessel and the marginal .edge of the closure member 121. A piston. having a stem 126 slidably mounted in the sleeve 120 and a head 127 which contacts the undersurface of the flexible diaphragm is located in the lower portion of the measuring vessel. A compression spring 128 is located between the undersurface of the piston head and the lower inner surface of the cylindrical portion of the measuring vessel.

The inlet and outlet valves s2 and 53 (Figs. 11 and' 13) are substantially identical, therefore, a detailed description of one of such valves will suffice. Each of these valves include a body member 130 adjustably mounted by screws V131 upon a bracket 132, which bracket is in turnmounted upon the mounting plate 90. An adjusting screw 133 is provided for locating the valve relative to the cam- 45, to be referred to hereinafter. The valve body member 130 has a well portion 135 adapted to receivea compression spring 136 for urging the valve head 137 into engagement with the valve seat 138. The valve seat is located on one end of a plug member 139 that is screw-threaded into the valve body. A valve stem 140 reciprocates within the plug member 139 and has a cap or spacer 141 on the upper portion thereof, which spacer contactsV a flexible diaphragm 142 held in position by a plug 143 that is screw-threaded into the upper portion of the valve body. An annular channel 144 is provided in the plug member 139 for flow of water from the inlet to the outlet when the valve is open. A reciprocating shaft 145 having a head 146 on the lower portion thereof is mounted in a bore of the valve plug 143, and the opposite end of the shaft lies adjacent a cam surface 45a onthe cam 45. A cam follower 147 made of a 9 suitable wear-resistant material is located between the end of the valve shaft 145 and the cam surface 45a. The valve shaft 145 may be made of nylon or other material which does not wear the cam surfaces, in which case the cam followers 147 may be omitted. A second cam surface 45h on cam 45 operates the valve shaft 145 of the outlet valve 53. The cam surfaces 45a, 45h, and 45C form integral parts of the cam 45 and are shaped in the manner shown in Figs. 11 and 13. The cam surface 45a operates the shaft 145 of the inlet valve 52; the cam surface 45b operates the shaft 145 of outlet valve 53; and the cam surface 45e operates the micro switch 46. As stated above, the specific valve and water measuring arrangement described above is the invention of Clyde E. Ploeger and is disclosed and claimed in his copending patent application, Serial No. 325,085, filed December 10, 1952.

For clarity of illustration, the ejector motor 40 is omitted from Fig. 13. The microswitch 46 is mounted on a bracket 150 by screws 151 and the bracket 1511 is adjustably mounted on the mounting plate 90 by screws 152. The microswitch includes a spring pressed plunger 153 which rides upon the perimeter of the cam 45C in a manner that the circuit to the ejector motor 40 is closed when the plunger is on the high portion of the cam and open when it is on the low portion as shown in Fig. 13.

The conduit 116 leading from the outlet valve 53 to the ice mold 32 includes a water diverter 156 (Figs. 1l and 12). The diverter includes a body member 157 having a restricted passageway 158 connected to the conduit 116 and an enlarged or unrestricted passageway 159. A drain conduit 160 having a vent opening 161 therein leads from the unrestricted passageway 159 to a suitable place of disposal. The water tube 81, made of plastic or other thermal insulating material, is connected at one end to the enlarged passageway 159 and at its opposite end this tube fits into the boss 80 on the plastic closure member 66 of the ice mold. rThe function of the diverter 156 is to prevent the freezing of water in the conduit 81 leading to the ice mold. That is, when the outlet valve 53 is open, water is forced from the measuring vessel 54 through the outlet valve and conduit 116 into and through the restricted passageway 158 and from there through the tube 81 to the rear compartment of the ice mold. And when the outlet valve is closed, any water that may leak past this valve falls from the restricted passageway 158 into the drain conduit 160, without entering the tube 81. The drip water that ows into the drain conduit 160 may be disposed of in any suitable manner, not shown. The

vent opening 161 in conduit 160 prevents the siphoning of water through this conduit. This specific manner of preventing the blocking of the water tube 81 by the accumulation of frozen drip water therein is the invention of Sven W. E. Andersson and is disclosed and claimed in his copending patent application, Serial No. 325,146, tiled` Refrigerator As shown in Figs. 10 and 14, the ice maker indicated generally by reference numeral 15, is located within a refrigerator 170. The refrigerator is divided by an insulated partition 171 into a freezing compartment 172, which contains the ice maker, and a food storage compartment 173. The freezing compartment is enclosed by a liner 174 having a metal bottom wall 175 placed in good thermal contact with a refrigerating coil 176 for maintaining this compartment of the refrigerator at low temperatures of between and 8 F. The liner 174 has a recess 177 in the upper left side thereof to receive the upper part of the ice maker, and the ice storage receptacle 27 rests on the bottom wall 175 beneath the ice maker. The partition 171 is spaced from the rear inner wall of the refrigerator for limited ow of air from the food storage compartment 173 across the refrigerating coil 176 and back to such compartment for maintaining temperatures of between 35 and 40 F. therein. The freezing compartment is closed by an inner door 177 (Fig. 14) and an outer door 178 closes' the entire open front of the refrigerator. The door switch 34, referred to above, is operated by the outer door 17S. A plurality of shelves 179 and a pair of vegetable fresheners 180 are located within the food storage comparment. A temperature control disk 25e for adjusting the box thermostat 25 is located at the bottom of the refrigerator, and the bulb 25b (Fig. 10) is placed in thermal contact with the refrigerating coil 176. A lever c Figs. 1 and 14 for operating the manual switch 20 is located on the side wall of the food storage compartment 173.

Operation In operation, assuming that the manual switch 20 is in the ice making position of Fig. 1, that the outer door of the refrigerator is closed and that the ice storage receptacle 27 is not yet illed with ice, in other words, the ice maker is energized. As the freezing of the water in the mold proceeds in the manner described above, when cube No. 7, the last to freeze, is completely frozen, the tem` perature of the bulb 28a of the mold thermostat falls to about F. which causes the switch 29 to shift from terminal 31 to terminal 30, thereby energizing the ejector motor and the mold heater 41. With switch blade 29 in contact with terminal 30, current flows from L1 through switch blade 2Gb, connector 20d, switch blade 20a, terminal 23, mercury switch 26, terminal 30, switch blade 29, switch blade 34a, terminal 35 and ejector motor 40 to L2. The motor begins to rotate the ejector shaft and attached blades 44 from the position shown in Fig. 7, thereby discharging the previously frozen and dried batch of ice from the blades into the storage receptacle 27 (Fig. 10). At the 45 point of rotation the high portion of cam 45b (Figs. 1 and 13) draws away from the shaft 145 of the water outlet valve 53 whereupon this valve closes. When the motor has rotated the ejector shaft about from the starting position of Fig. 7, the high portion of the cam 45e (Fig. 1) operates the plunger 153 of the microswitch 46 which shifts this switch from terminal 48 to terminal 47 which deenergizes the compressor motor 24, energizes the mold thermostat heater 50 and establishes a circuit for the ejector motor between the terminal 47 and terminal 31. At about the 135 point of rotation of the ejector shaft 43 the cam 45a opens the inlet water valve 52 feeding a measured charge of water to the measuring vessel 54 which extends the diaphragm 123 and compresses the spring 128 in the lower part of the measuring vessel, as shown in Figs. l and 11. Rotation of the ejector motor and the blades 44 continue until at about 180 of rotation the blades contact the ice frozen solid in the mold which causes the energized motor to stall. The mold heater 41 continues to heat the mold to free the ice therefrom, and the reset heater 50 continues to heat the mold thermostat bulb 28a s'o as to reset the switch 29 in contact with terminal 31 as shown.

When the ice is thawed free of the mold, rotation of the ejector motor 40 and attached blades 44 continues Whether or not the mold thermostat has reset the switch 29 to the position shown in Fig. 1. If the switch 29 has not reset, current flows from terminal 30 to the ejector motor, and if this switch has reset current ows from terminal 31. As the motor continues to rotate the ejector blades the ice is slowly rotated and swept from the mold, and at about 225 of rotation the low portion of cam 45a is opposite the shaft of the inlet valve 52 whereupon the spring 136 (Fig. 13) closes this valve. Rotation of the motor continues and when the blades 44 reach the 270 pointV of rotation the cam 56 quickly raises the channelA member. 100. from thefull to the broken line position of Fig. 4, whereupon the circuit through the mercury switch107 is opened. If the switch 29 has reset and is in contact with terminal 31 (Fig. l), the opening of the mercury switch does not deenergize the ejector motor since it is getting current from terminal 47 'of the vmicroswitch and terminal '31 of the mold thermostat switch. However, if the thermostat switch has not reset, opening of the mercury switch stops the'operation of the ice maker since the ejector motor 40 was getting current from terminal 30 of the mold thermostat switch 29. The reset heater 50 remains energized, trying to reset the switch 29, and .if it is successful, rotation of the ejector motor continues; but if it is not successful, 'it means that the thermostat -28 haslo'st its charge or is' otherwise defective, cannot be' reset, and the system dies permanently, with theejector motor 40 and mold heater 41 deener'gized,'the compressor motor deenergized, the reset heater energized, andthe inlet and outlet valves' 52 and' 53 closed.

`Returning now to where .the mercury switch 10,7l opened its circuit, the ejector blades are at the 270 point of rotation, but the thermostat switch 29 has reset. Rotation continues since the ejector `motor is getting current from terminal 31. Atabout the 300 point of rotation the channel member 100 and attached mercury switch falls free of the cam 56 and the circuit is either made or not, depending upon how much ice is in the storage receptacle 27. If the storage receptacle is filled with ice, the circuit through the mercury switch is not closed at this point, and although the-motor will continue to rotate and complete an ice release cycle, a new cycle cannot be instigated until some ice has been removed from the storage receptacle, thereby permitting the mercury switch to close. Also, at about the 315 point of rotation of the ejector, the high portion of cam -45b (Fig. l) is opposite the shaft 145 of the outlet valve 53 whereupon this valve is opened and the measured quantity-of water is forced from the measuring vessel 54 through the Aconduit 116, the vdiverter 156 and the tube 81 into the rear compartment of the ice mold. The water flows from the rear compartment to the forward compartments through the wiers 63 (Fig. 3), thereby establishing a common level of water in the several compartments. The wiers 63 also provide a bridge member of ice connecting adjacent ice cubes when frozen.

The ejector motor 40 is still receiving current through terminal 31 (Fig. 1)'from terminal 47 of the microswitch so that the motor continues to rotate the ejector blades which finally sweep the ice from the mold and at tile 360 point of rotation the plunger 153 of the microswitch enters the notch or low portion of the cam 45C whereupon the microswitch is shifted from terminal 47 to terminal 48 and the ejector motor is stopped with the ice resting in an upside down position on the ejector blades, as shown in Figs. 2 and 7. Thus, the ejector is back at the starting point with the ejector motor 40, the mold heater 41 and the reset heater Si) deenergized, the compressor motor 24 energized, thermold filled with water, the inlet valve 52 closed, the outlet .valve 53 open, and a new freezing cycle begins. Should any water drip into the diverter`156 during a freezing -cycle of operation, such wateris diverted through the drain conduit 160 to a placeof disposal, and this drip water does not enter the tube 81 leading to the ice mold. y

It is to be noted that the part of the ice cubes that contact theejectorshaft and blades during the drying period, the freezing period of a subsequent batch of cubes, is the top surface of the ice during the thawing-period, which top surface is not wetted by the thawing, and consequently, there is substantially no bond between the ice and the ejector. However, should there be some sticking of the ice to the ejector, as-by an accumulation of` frost due to prolonged standing when the storage receptacle is filled with the ice maker stands idle, the bond is broken by contact of the ice with the projections 62 at the right side ofthe mold partitions at the beginning of an ejecting cycle. VThis follows because the lower right hand surface of the ice pieces in the drying position is of greater extent than the span between the projections 62 on the right side of the partitions, the partitions being tapered outward of the mold compartments from right to left (Fig. 8), and when the ejector begins a release cycle the bottom right edges of the ice contact the projections 62 (Fig. 7) which strip the ice from the ejector. The arcuate outer surface of the wiers 63 offer no resistance to the turning movement of the ice cubes, and the upstanding edge 64 along the top left side ofthe mold (Fig. 4) aids in bringing the ice cubes to rest in the upside down positien on the ejector (Fig. 7) as the cubes are swept from the mold. lt is also to be noted that when the storage receptacle is filled with the desired quantity of ice, and the ice maker stands idle due to the opening of the stop switch 26, there is ice at three stations: (l) the storage station, the receptacle 27; (2) the drying station, on the ejector; and (3) the freezing station, the ice frozen in the mold. So that when ice is removed from the storage receptacle and the stop switch 26 closes, there is immediately available a batch of Dry Ice on the ejector to be discharged into the storage receptacle and a second batch of ice in the mold to be ejected therefrom to the drying station on the ejector.

In the above description, a compression type refrigerating system is used as one means for freezing the water in the ice mold. However, other types of refrigerating systems may be used with equal facility. For example, an absorption type refrigerating system may be used, in which case, should it be desired that operation of such system be interrupted during the ice release periods, the heat suppiy to the system may be controlled by the microswitch 46. That is, the fuel supply to a burner or the electric supply to an electric heating element for the refrigerant generator may be controlled by the same mechanism that controls the compressor motor 24.

Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art to which this invention appertains, and it will, of course, be understood that changes in form, proportions and minor details of construction may be resorted to without departing from the spirit of the invention and scope of the claims.

What is claimed is:

l. An automatic ice maker including an ice mold having a plurality of ice forming compartments, refrigerating means for forming ice in said compartments, means associated with one of said compartments for retarding the formation of ice in said one compartment, and vmeans incorporated in said ice maker and operative responsive to the formation of ice in said one compartment for discontinuing the operation ofthe refrigerating means.

2. An ice maker as set forth in claim 1 wherein a surface of said one compartment is formed at least in part of a material of low heat conductivity relative to the material forming the surface of the other of said plurality of compartments.

3. An ice maker as set forth in claim 2 wherein the means for discontinuing the operation of the refrigeration means includes a thermostat associated with the surface of said one compartment having low heat conductivity, and

wherein a heat transfer element of relatively high heat conductivity is placed in contact with water in said one compartment and with said thermostat.

4. An automatic ice maker including an ice mold having a plurality of ice forming compartments, one of said compartments having one wall thereof constructed and arranged to transfer heat therefrom at a relatively low rate in comparison with the heat transfer rate of the remainder of the mold, means for freezing water in the mold, ejector mechanism incorporated in the ice maker 13 for simultaneously removing ice from each of the ice forming compartments, and control means operative responsive to the complete formation of ice on said one wall for energizing said ejector mechanism.

5. An ice maker as set forth in claim 4 wherein said control means includes a thermostat in said one wall and means for heating said thermostat.

6. An ice maker as set forth in claim 7 wherein the heating means includes a heat transfer element for conducting heat between water in said one compartment of the mold and the thermostat.

7. An ice maker as set forth in claim 7 wherein the heating means includes an element operative responsive to the formation of ice on said one wall for heating the thermostat.

8. An automatic ice maker including an ice mold having a plurality of ice forming compartments, refrigerating means for forming ice in said compartments, at least one of said compartments having a wall thereof formed of heat insulating material whereby the formation of ice in said one compartment is retarded, and means incorporated in said ice maker and operative responsive to the formation of ice in said one compartment for removing ice from said plurality of compartments.

9. An ice maker as set forth in claim 8 wherein said removing means includes a thermostat located in the Wall of heat insulating material of said one compartment in a manner to be insulated from the water in the mold and from the ambient, and means for placing said thermostat in heat exchange relation with water in said one compartment.

10. An ice maker as set forth in claim 9 that includes heating means for freeing the ice from the mold, and means for placing the thermostat in heat exchange relation on the ejector (Fig. 7) as the cubes are swept from ll. in an automatic ice maker, an ice mold having a plurality of heat transfer surfaces with at least one of said heat transfer surfaces being constructed and arranged to transfer heat therefrom at a relative low'rate in comparison with the heat transfer rate of the remainder of said heat transfer surfaces whereby water in Contact with said one heat transfer surface is last to freeze, means for filling the mold with water,` refrigerating means for completely freezing all of the water in the mold, and mechanism incorporated in the ice maker and operative responsive only to the complete freezing of water in contact with said one heat transfer surface for removing ice from the mold.

l2. In an automatic ice maker, an ice mold, means for dividing the mold into a plurality of ice forming compartments, means for filling the mold with water to be frozen, refrigerating means for freezing the water in the mold, means for freeing the ice from the mold, means mounted on the ice maker for removing the ice from the mold and control means for said filling, freeing and removing means, said ice mold having one compartment thereof at least partially insulated from the freezing meanswhereby the water is completely frozen in the other of the plurality of compartments before being completely frozen in said one compartment, and said control means being operative responsive to the complete freezing of the water in said one compartment.

13. An automatic ice maker as set forth in claim l2 wherein the control means includes a thermostat having a temperature sensing element thereof insulated from the water in said one compartment, and a heat transfer element of relatively high heat conductivity arranged in heat exchange relation between the water in said one compartment and the temperature sensing element whereby said element follows the temperature of the water in said one compartment.

14. An automatic ice maker as set forth in claim l2 wherein said freeing means includes a heating element energized by the complete freezing of waterin said one compartment, and wherein the control means includes a thermostat having a temperature sensing element arranged in heat exchange relation with water in said one compartment and with said heating element.

l5. An automatic ice maker as set forth in claim 12 wherein the ice removing means includes a rotatable element and a motor for driving said rotatable element, and wherein said motor is energized responsive to the complete freezing of the Water in said one compartment.

16. An automatic ice maker as set forth in claim 12 wherein the ice removing means includes an ejector rotatable through the ice mold compartments, an electric motor for driving said ejector, and said control means includes a iirst switch operative responsive to the complete freezing of water in said one compartment for energizing said motor, and means operative responsive to rotation of the ejector for deenergizing the motor.

17. In an automatic ice maker, an ice mold having a plurality of ice forming compartments, refrigerating means for forming ice in said compartments, and control means operative responsive to the formation of ice in one only of said compartments for discontinuing the operation of said refrigerating means, said control means including a thermostat generally insulated from said ice mold and from the ambient and having a temperature sensing element thereof in limited heat exchange relation with water in said one compartment whereby the operation of the refrigerating means is discontinued only after the water has been completely frozen in said one compartment.

18. An automatic ice maker as set forth in claim 17 which includes means for iilling the mold with Water and means for removing ice from the mold, and wherein the ice mold is filled with water and operation of the refrigerating means is resumed responsive to the removal of ice from the mold.

` 19. ln an automatic ice maker, an ice mold, means for filling the mold with water to be frozen, refrigerating means for freezing the water into ice in the mold, means incorporated in the ice maker for removing the ice from the mold and control means for the filling, refrigerating and ice removing means, said control means including a thermostat operative responsive to the freezing of water in the mold to instigate operation of said control means, said thermostat being of a type that is hermetically sealed and charged with a uid the pressure of which changes with changes in temperature, and means incorporated in the control to automatically prevent operation of the control means upon loss of charge of the thermostat.

20. An automatic ice maker as set forth in claim 19 wherein the thermostat includes a diaphragm system so charged with a fluid as to operate above atmospheric pressure and instigate operation of the control means on falling pressure and wherein said control means is rendered inoperative upon loss of charge of the thermostat.

21. In an automatic ice maker, an ice mold, means for iilling the mold with water to be frozen, refrigerating means for freezing the water into ice in the mold, control means for instigating operation of the filling means, said control means including a thermostat and a switch movable thereby to one position by the freezing of water in the mold to instigate the filling of the mold and movable to a second position by a release of ice from the mold to discontinue operation of the filling means, and means arranged and connected with the control means and operated thereby to prevent instigation of the filling means upon failure of the switch to move to the second position.

22. in an automatic ice maker, an ice mold, means for filling the mold with water to be frozen, refrigerating means for freezing the water in the mold, means including an electric motor for removing the ice from the mold, a storage receptacle for receiving ice from the removing means, and control means for said lilling and removing means, said control means including a thermostat, a rst electric circuit having a first and a second switch therein for energizing and deenergizing said motor, the first switch being operativeby they thermostat responsive to the formationof ic'e in Vsaid mold for closing said first circuit and the second switch being operative lresponsive to the accumulationof ice in said storage receptacle for opening said rst circuit when the receptacle contains a given amount of ice and for closing said first circuit when the receptacle contains less than the given amount, a second electric' circuit having a third switch therein for energizing said motor even though the first circuit be opened by either or both of the first and second switches therein, the first switch being movable to a first position for closing the fir'st circuit and opening the second circuit responsive to a freezing temperature of the ice mold and movable to` a second position for opening the first circuit and closing the second circuit responsive to a thawing temperature of the ice mold, and thermal means for causing the'thermostat to move said first switch to the second positiony irrespective of the temperature of the ice mold.

23. An automaticice maker as set forth in claim 22 whereinthe second switch in the first circuit is movable to open position' by said motor and when moved to open position deenergizes the motor in case the thermostat fails to move the first switch to the second position.

24. An automatic ice maker as set forth in claim 22 whereinthe filling means is rendered inoperative in case of failure of the thermostat.

25. An automatic ice maker as set forth in vclaim 22 wherein the filling, freezing and removing means are rendered inoperative in case of failure of the thermostat.

26. An automatic ice maker as set forth in claim 22 wherein the opening of the second switch in the first circuit renders the filling, freezing and removing means inoperative in case the first switch in said circuit has not moved to the second position.

27. An automatic ice maker as set forth in claim 22 which includes a'third circuit for energizing the refrigerating means and which circuit is opened and closed by the third switch in the second circuit.

28. In an ice maker, the combination with a multicompartment mold, a drying station, a storage station, and refrigerating apparatus arranged to produce freezing ternperatures at said mold and said stations, said mold having one compartment thereof at least partially insulated from the freezing temperatures produced by the refrigerating apparatus, of a member so constructed and aranged as to move relative to the mold and engage ice pieces formed by the mold, mechanism arranged and connected to operatesaid member to'remove from the mold ice pieces, conduct them to the drying station and release them to the storage station, and a control to instigate operation of said mechanism operative responsive to the complete freezingv of water into ice in said one mold compartment. y

29. In an ice maker, a multi-compartment, a drying station, 'a storage station, refrigerating apparatus arranged to producefreezing temperatures in said mold and said stations, said'mold having one compartment thereof at least partially insulated from the freezing temperatures produced-by the refrigerating apparatus, a member so constructed and arranged as to move relative to said mold and engage ice pieces formed by the mold, mechanism arranged and connected to operate said member to remove from the mold ice pieces and conduct them to the drying station, and a control operative responsive to the complete freezing of water into ice in said one compartment of the mold to instigate operation of said mechanism, said member also being so constructed and arranged as to release ice pieces from said drying station to said storage station upon operation of said mechanism 30. In an ice maker, a multi-compartment mold, refrigerating apparatus arranged to freeze water in the mold, said mold being so constructed and arranged relative to the refrigerating apparatus as to contain unfrozen water in one of the mold compartments subsequent to the corninto ice'in saidV one 4compartment of the mold to startY operation of saidmechanism and-.stop such operation at the endof each cycle, `anda device at said second storage station constructedv and rarranged to prevent operation of said'control when a desiredquantit-y of ice is in said second storage station.

3l. In an ice maker, a multi-compartment mold, a drying station, a storage station, refrigerating apparatus arrangedto produce freezing temperatures at said mold and said stations, said mold having one compartment thereof so constructed and :arranged relative to the refrigerating apparatus Vas to lcontain water subsequent to the complete freezingofwaterin the other of the mold compartments,.mechanism operativeto transfer ice pieces from ,thedrying station .to the storage station and other ice pieces from the ymold Vto the drying station in one cycle .of operation, a control initiated by the complete freezingof water into icein said one compartment of the mold to start operation of said;mechanism and stop such operation at the end of each cycle, and a device at said storage ,station Yconstructed and arranged to prevent operation of said control while a desired quantity of ice is in said storage station.

32. :In an ice maker, the .combination with a multicompartment mold, a drying station, a storage station, and refrigeration apparatus arranged to produce freezingtemperatures at ysaid mold. and said stations, said mold having one compartment thereof so constructed and arm ranged relative to the refrigerating ,apparatus as to contain water subsequent to the complete freezing of water into vice in the other of the mold compartments, of a member so constructed and arranged as to move relative to the mold and engage ice pieces formed by the mold, mechanism arranged and connected to operatezsaid member to transfer ice pieces from the drying `station to the storage station andother ice pieces from the mold to the drying station in onecycle lof operation, a control initiated by change in a condition affected by the complete freezing of water into ice in said one compartment of the mold to start operation of said mechanism and stop operation at the end of eachcycle, and a device at said storage station constructed and arranged vto prevent operation of said control While a desired quantity of ice is in said storage station.

33. A refrigeratorhaving va compartment therein and a door `for closing saidrcompartment, an automatic ice makerwithin said compartment, and refrigerating means for cooling said compartment and said ice maker, said ice maker including means for freezing, harvesting and storing Vice pieces and control mechanism therefor, and said control mechanism including a plurality yof electric cir- .cuits having a pluralityof switches therein, said plurality of switches including a vfirst switch operative responsive to the freezing of ice in theicevmaker for energizing said harvesting' means, -a second switch operative responsive to actuation of the harvesting means to continue the Venergizationthereof independently of the rst switch and to deenergize .the refrigerating means, a third switch operative responsive to the opening of the refrigerator j kdoor-.for deenergizing the harvesting means, a fourth switch operative responsive to the accumulation of ice in the storage means for deenergizing the harvesting means and a fifth switch operative to deenergize the harvesting vmeans and to energize the refrigerating means independently of the other of'said plurality of switches.

34. A method vof automatically producing ice which comprises transferring heat from water to a-first portion of a heat transferV surface at'one rate -of heat transfer to 'thereby form iceon Asaid portion of the heat transfer surface while holdingwater in a liquid state on a second Y 17 portion of the heat transfer surface, transferring heat from the Water held on the second portion of the heat transfer surface at a second and slower rate of heat transfer to thereby completely freeze such water and form ice on the second portion of the heat transfer surface subsequent to the formation of ice on the rst portion of the heat transfer surface, and removing ice from the the whole of heat transfer surface reponsive to the complete formation of ice on the second portion thereof.

35. A method of automatically producing pieces of ice which comprises filling a mold with water, progressively freezing the water into ice in a manner that a quantity of unfrozen water is trapped in the ice, and discontinuing the freezing responsive to the complete freezing of the trapped water substantially coincident therewith.

36. A method of automatically producing pieces of ice which comprises lling a mold with water, progressively freezing the water into ice in a manner that a quantity of unfrozen Water is trapped in the ice, and removing the ice from the mold responsive to the complete freezing of the trapped Water immediately following the complete freezing thereof.

37. A method of automatically producing pieces of ice which comprises filling a multi-compartment mold with Water, progressively freezing the water in the mold in a manner that the water is completely frozen in at least one of said mold compartments before being completely frozen in a second of said mold compartments and discontinuing the freezing responsive to the complete freezing of Water in the second of said mold compartments substantially coincident therewith.

38. A method of automatically producing pieces of ice which comprises lling a multi-compartment mold with 18 water, freezing the water in a manner that one compartment of the mold contains water subsequent to the substantial complete freezing of the water into ice in the other compartments of the mold and simultaneously removing ice from all of the mold compartments responsive to the complete freezing of the water in said one compartment immediately following the complete freezing thereof.

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